makeGif.py

# Tom Arrell
# Animated Face Gif Creator

# run:
# python makeGif.py './MySquareImage.png'

import sys
from PIL import Image
import StringIO
import math as Math

FRAMES = 36
DEGREES = 10
SIZE = 32

# Make the initial image a square. Find the smallest size
# and crop to it to a square based on that from the top left corner.
def cropToSquare(image):
  minDimension = min(image.size)
  return image.crop((0, 0, minDimension, minDimension))

# Find the max edge width of a diamond that can fit in the square
# as it rotates.
def maxDiamondWidth(image):
  width, height = image.size
  if (width != height):
    raise Exception('Image is not square')
  return Math.floor(Math.sqrt((width / 2)**2 + (width / 2)**2))

def calcCenterOffset(image, toCenterWidth):
  imageWidth = image.size[0]
  return Math.floor((imageWidth / 2) - (toCenterWidth / 2))

def main():
  cliArgs = sys.argv
  fileName = cliArgs[1]
  imageArray = []

  im = Image.open(fileName)
  im = cropToSquare(im)

  # Calculate diamond width and offset to center crop frame
  maxWidth = maxDiamondWidth(im)
  offset = calcCenterOffset(im, maxWidth)

  for i in range(FRAMES):
    newIm = im
    newIm = newIm.rotate(DEGREES * i, resample=Image.BICUBIC)
    cropped = newIm.crop(
      (offset, offset, maxWidth + offset, maxWidth + offset)
    ).resize((SIZE, SIZE), resample=Image.BICUBIC)

    buff = StringIO.StringIO()
    cropped.save(buff, 'png', optimize=True)
    imageArray.append(Image.open(buff))

  # Write the image array to disc as a new GIF file
  imageArray[0].save(
    'output.gif',
    save_all=True,
    append_images=imageArray[1:],
    duration=40,
    loop=0
  )

main()